xref: /titanic_41/usr/src/cmd/sgs/libelf/common/ar.c (revision 6f45ec7b0b964c3be967c4880e8867ac1e7763a5)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  *	Copyright (c) 1988 AT&T
24  *
25  *	  All Rights Reserved
26  *
27  */
28 
29 /*
30  * Copyright (c) 1999 by Sun Microsystems, Inc.
31  * All rights reserved.
32  */
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI" 	/* SVr4.0 1.6	*/
35 
36 #include "syn.h"
37 #include <ar.h>
38 #include <stdlib.h>
39 #include <memory.h>
40 #include <errno.h>
41 #include <libelf.h>
42 #include "decl.h"
43 #include "msg.h"
44 #include "member.h"
45 
46 #define	MANGLE	'\177'
47 
48 
49 /*
50  * Archive processing
51  *	When processing an archive member, two things can happen
52  *	that are a little tricky.
53  *
54  * Sliding
55  *	Sliding support is left in for backward compatibility and for
56  *	support of Archives produced on other systems.  The bundled
57  *	ar(1) produces archives with all members on a 4 byte boundry,
58  *	so current archives should need no sliding.
59  *
60  *	Archive members that are only 2-byte aligned within the file will
61  *	be slid.  To reuse the file's memory image, the library slides an
62  *	archive member into its header to align the bytes.  This means
63  *	the header must be disposable.
64  *
65  * Header reuse
66  *	Because the library can trample the header, it must be preserved to
67  *	avoid restrictions on archive member reuse.  That is, if the member
68  *	header changes, the library may see garbage the next time it looks
69  *	at the header.  After extracting the original header, the library
70  *	appends it to the parents `ed_memlist' list, thus future lookups first
71  *	check this list to determine if a member has previously been processed
72  *	and whether sliding occured.
73  */
74 
75 
76 /*
77  * Size check
78  *	If the header is too small, the following generates a negative
79  *	subscript for x.x and fails to compile.
80  *
81  * The check is based on sizeof (Elf64) because that's always going
82  * to be at least as big as Elf32.
83  */
84 
85 struct	x
86 {
87 	char	x[sizeof (struct ar_hdr) - 3 * sizeof (Elf64) - 1];
88 };
89 
90 
91 
92 static const char	fmag[] = ARFMAG;
93 
94 
95 /*
96  * Convert a string starting at 'p' and ending at 'end' into
97  * an integer.  Base is the base of the number being converted
98  * (either 8 or 10).
99  *
100  * Returns the converted integer of the string being scaned.
101  */
102 unsigned long
103 _elf_number(char * p, char * end, int base)
104 {
105 	register unsigned	c;
106 	register unsigned long	n = 0;
107 
108 	while (p < end) {
109 		if ((c = *p - '0') >= base) {
110 			while (*p++ == ' ')
111 				if (p >= end)
112 					return (n);
113 			return (0);
114 		}
115 		n *= base;
116 		n += c;
117 		++p;
118 	}
119 	return (n);
120 }
121 
122 
123 /*
124  * Convert ar_hdr to Member
125  *	Converts ascii file representation to the binary memory values.
126  */
127 Member *
128 _elf_armem(Elf * elf, char * file, size_t fsz)
129 {
130 	register struct ar_hdr	*f = (struct ar_hdr *)file;
131 	register Member		*m;
132 	register Memlist	*l, * ol;
133 	register Memident	*i;
134 
135 	if (fsz < sizeof (struct ar_hdr)) {
136 		_elf_seterr(EFMT_ARHDRSZ, 0);
137 		return (0);
138 	}
139 
140 	/*
141 	 * Determine in this member has already been processed
142 	 */
143 	for (l = elf->ed_memlist, ol = l; l; ol = l, l = l->m_next)
144 		for (i = (Memident *)(l + 1); i < l->m_free; i++)
145 			if (i->m_offset == file)
146 				return (i->m_member);
147 
148 	if (f->ar_fmag[0] != fmag[0] || f->ar_fmag[1] != fmag[1]) {
149 		_elf_seterr(EFMT_ARFMAG, 0);
150 		return (0);
151 	}
152 
153 	/*
154 	 * Allocate a new member structure and assign it to the next free
155 	 * free memlist ident.
156 	 */
157 	if ((m = (Member *)malloc(sizeof (Member))) == 0) {
158 		_elf_seterr(EMEM_ARMEM, errno);
159 		return (0);
160 	}
161 	if ((elf->ed_memlist == 0) || (ol->m_free == ol->m_end)) {
162 		if ((l = (Memlist *)malloc(sizeof (Memlist) +
163 		    (sizeof (Memident) * MEMIDENTNO))) == 0) {
164 			_elf_seterr(EMEM_ARMEM, errno);
165 			return (0);
166 		}
167 		l->m_next = 0;
168 		l->m_free = (Memident *)(l + 1);
169 		l->m_end = (Memident *)((uintptr_t)l->m_free +
170 			(sizeof (Memident) * MEMIDENTNO));
171 
172 		if (elf->ed_memlist == 0)
173 			elf->ed_memlist = l;
174 		else
175 			ol->m_next = l;
176 		ol = l;
177 	}
178 	ol->m_free->m_offset = file;
179 	ol->m_free->m_member = m;
180 	ol->m_free++;
181 
182 	m->m_err = 0;
183 	(void) memcpy(m->m_name, f->ar_name, ARSZ(ar_name));
184 	m->m_name[ARSZ(ar_name)] = '\0';
185 	m->m_hdr.ar_name = m->m_name;
186 	(void) memcpy(m->m_raw, f->ar_name, ARSZ(ar_name));
187 	m->m_raw[ARSZ(ar_name)] = '\0';
188 	m->m_hdr.ar_rawname = m->m_raw;
189 	m->m_slide = 0;
190 
191 	/*
192 	 * Classify file name.
193 	 * If a name error occurs, delay until getarhdr().
194 	 */
195 
196 	if (f->ar_name[0] != '/') {	/* regular name */
197 		register char	*p;
198 
199 		p = &m->m_name[sizeof (m->m_name)];
200 		while (*--p != '/')
201 			if (p <= m->m_name)
202 				break;
203 		*p = '\0';
204 	} else if (f->ar_name[1] >= '0' && f->ar_name[1] <= '9') { /* strtab */
205 		register unsigned long	j;
206 
207 		j = _elf_number(&f->ar_name[1],
208 			&f->ar_name[ARSZ(ar_name)], 10);
209 		if (j < elf->ed_arstrsz)
210 			m->m_hdr.ar_name = elf->ed_arstr + j;
211 		else {
212 			m->m_hdr.ar_name = 0;
213 			/*LINTED*/ /* MSG_INTL(EFMT_ARSTRNM) */
214 			m->m_err = (int)EFMT_ARSTRNM;
215 		}
216 	} else if (f->ar_name[1] == ' ')			/* "/" */
217 		m->m_name[1] = '\0';
218 	else if (f->ar_name[1] == '/' && f->ar_name[2] == ' ')	/* "//" */
219 		m->m_name[2] = '\0';
220 	else {							/* "/?" */
221 		m->m_hdr.ar_name = 0;
222 		/*LINTED*/ /* MSG_INTL(EFMT_ARUNKNM) */
223 		m->m_err = (int)EFMT_ARUNKNM;
224 	}
225 
226 	m->m_hdr.ar_date = (time_t)_elf_number(f->ar_date,
227 		&f->ar_date[ARSZ(ar_date)], 10);
228 	/* LINTED */
229 	m->m_hdr.ar_uid = (uid_t)_elf_number(f->ar_uid,
230 		&f->ar_uid[ARSZ(ar_uid)], 10);
231 	/* LINTED */
232 	m->m_hdr.ar_gid = (gid_t)_elf_number(f->ar_gid,
233 		&f->ar_gid[ARSZ(ar_gid)], 10);
234 	/* LINTED */
235 	m->m_hdr.ar_mode = (mode_t)_elf_number(f->ar_mode,
236 		&f->ar_mode[ARSZ(ar_mode)], 8);
237 	m->m_hdr.ar_size = (off_t)_elf_number(f->ar_size,
238 		&f->ar_size[ARSZ(ar_size)], 10);
239 
240 	return (m);
241 }
242 
243 
244 /*
245  * Initial archive processing
246  *	An archive may have two special members.
247  *	A symbol table, named /, must be first if it is present.
248  *	A string table, named //, must precede all "normal" members.
249  *
250  *	This code "peeks" at headers but doesn't change them.
251  *	Later processing wants original headers.
252  *
253  *	String table is converted, changing '/' name terminators
254  *	to nulls.  The last byte in the string table, which should
255  *	be '\n', is set to nil, guaranteeing null termination.  That
256  *	byte should be '\n', but this code doesn't check.
257  *
258  *	The symbol table conversion is delayed until needed.
259  */
260 void
261 _elf_arinit(Elf * elf)
262 {
263 	char *				base = elf->ed_ident;
264 	register char *			end = base + elf->ed_fsz;
265 	register struct ar_hdr *	a;
266 	register char *			hdr = base + SARMAG;
267 	register char *			mem;
268 	int				j;
269 	size_t				sz = SARMAG;
270 
271 	elf->ed_status = ES_COOKED;
272 	elf->ed_nextoff = SARMAG;
273 	for (j = 0; j < 2; ++j)	 {	/* 2 special members */
274 		unsigned long	n;
275 
276 		if (((end - hdr) < sizeof (struct ar_hdr)) ||
277 		    (_elf_vm(elf, (size_t)(SARMAG),
278 		    sizeof (struct ar_hdr)) != OK_YES))
279 			return;
280 
281 		a = (struct ar_hdr *)hdr;
282 		mem = (char *)a + sizeof (struct ar_hdr);
283 		n = _elf_number(a->ar_size, &a->ar_size[ARSZ(ar_size)], 10);
284 		if ((end - mem < n) || (a->ar_name[0] != '/') ||
285 		    ((sz = n) != n)) {
286 			return;
287 		}
288 
289 		hdr = mem + sz;
290 		if (a->ar_name[1] == ' ') {
291 			elf->ed_arsym = mem;
292 			elf->ed_arsymsz = sz;
293 			elf->ed_arsymoff = (char *)a - base;
294 		} else if (a->ar_name[1] == '/' && a->ar_name[2] == ' ') {
295 			int	k;
296 
297 			if (_elf_vm(elf, (size_t)(mem - elf->ed_ident),
298 			    sz) != OK_YES)
299 				return;
300 			if (elf->ed_vm == 0) {
301 				char *	nmem;
302 				if ((nmem = malloc(sz)) == 0) {
303 					_elf_seterr(EMEM_ARSTR, errno);
304 					return;
305 				}
306 				(void) memcpy(nmem, mem, sz);
307 				elf->ed_myflags |= EDF_ASTRALLOC;
308 				mem = nmem;
309 			}
310 
311 			elf->ed_arstr = mem;
312 			elf->ed_arstrsz = sz;
313 			elf->ed_arstroff = (char *)a - base;
314 			for (k = 0; k < sz; k++) {
315 				if (*mem == '/')
316 					*mem = '\0';
317 				++mem;
318 			}
319 			*(mem - 1) = '\0';
320 		} else {
321 			return;
322 		}
323 		hdr += sz & 1;
324 	}
325 }
326